132
FXUS66 KSTO 052013
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
113 PM PDT Sat Jul 5 2025

.DISCUSSION...

.SYNOPSIS...
Dry and breezy conditions continue today, with seasonably cool
afternoon high temperatures in the Valley. Warming trend begins
tomorrow, with triple digits in the northern Sacramento Valley and
mid to upper 90s elsewhere. Weak offshore low pressure on Sunday
could introduce an isolated (less than 10% chance) shower/t-storm
along the peaks of interior NorCal mountain ranges on Sunday and
Monday evening. Low daytime humidity values and breezy southerly
winds on Monday will introduce elevated fire weather conditions
for portions of the northern Sacramento Valley. Slight cooldown on
Tuesday, then warming trend again with the return of widespread
Moderate HeatRisk on Thursday and Friday.

&&

.KEY MESSAGES...

*  Today - Monday:
 - Onshore winds will keep temperatures below average today
 - Mostly dry weather, non-zero chance of afternoon/evening
   convection over the peaks of the Sierra, southern Cascades, and
   the Coastal Range. Higher resolution models keep most activity
   out of our area, so confidence is low on any storm development
   at this time.
 - Winds will be locally breezy at times, strongest through the
   Delta and over the higher elevations
 - Slow warming Sunday into Monday, with continued dry conditions
 - Elevated fire weather conditions for portions of the northern
   Sacramento Valley on Monday due to low daytime humidity values
   and breezy southerly winds, with gusts around 15-25 mph.
   Highest risk area: along and west of I-5 from around Corning to
   Redding.

*  Tuesday - Friday:
 - Increased onshore flow with below normal temperatures.
   Temperatures trend up by the end of the week with above normal
   highs with widespread Moderate HeatRisk Thursday and Friday

.Changes from previous forecast...
 - Elevated fire weather conditions are in the forecast for
   portions of the northern Sacramento Valley. Highest threat area
   is along and west of I-5, from Corning to Redding. Daytime
   humidity values: 15-20%, Southerly wind gusts around 15-25 mph.
   These conditions will lead to easier fire starts, especially in
   the afternoon/evening with peak daytime heating.
 - Non-zero (less than 10% chance) of an isolated mountain
   thunderstorm in the Sierra, southern Cascades, and Coastal
   Range Sunday and Monday. Confidence very low on any storm
   development at this time.

&&

.AVIATION...

VFR conditions across interior NorCal next 24 hours. Periods of
breezy onshore winds with gusts up to 20 knots in the Delta
vicinity. Elsewhere, surface winds generally below 12 kts.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$